I. Field of the Invention
The present invention relates generally to mobile, upright systems for cleaning vertical surfaces, especially truck trailer sides. More particularly, the present invention relates to mobile systems equipped with vertically upright rotating brushes of the type classified in United States Patent Class 15, Subclasses 52.2, 52.3, 53.1 and 53.2.
II. Description of the Prior Art
As will be readily appreciated, many large retailers and wholesalers operate their own tractor trailer rigs to haul goods to market. For tax and accounting reasons, many large trailers are rented or leased for a relatively short period of time, before being returned to the lessee. While most over-the-road tractor trailers are marked with advertisements, or the name of the trucking company or owner, not all are carefully painted. Instead, it is becoming increasingly common for these large trailers to be economically marked along both sides with very large, vinyl decals. Large tractor trailers can exceed ten feet in height, and may be up to fifty three feet or more long. Very large decals are thus required. These are installed at the commencement of the lease, and they must be removed at the completion of the lease period when the trailers are turned back to the lessee.
At this time the decals must be removed. Further, they must be non-destructively removed so as to minimize scarring or defacing of the outer trailer wall surfaces. With known prior art equipment it is very difficult and time consuming to remove such decals.
A number of portable, hand-held decal removal tools are known in the art. These small-but-handy devices are not equipped to handle fifty foot long truck decals. For example, U.S. Pat. No. 4,690,724 discloses structure designed to remove small, vinyl decals, but not the adhesive, from automotive surfaces. The tool is effective in removing small decals, but it is utterly insufficient for use with large truck decals as the labor costs and time required for success are prohibitive. Further, with this device, a solvent must thereafter be applied to remove the sticky adhesive. The tool could be used to remove a decal ten feet tall and fifty-three feet long.
U.S. Pat. No. 5,259,914 entitled "Portable Vehicle Adhesive Remover" discloses a portable device using a rotating eraser unit to remove decal material and adhesive from automotive surfaces. It is activated with air pressure. This small handheld device is designed for small applications such as the removal of small pinstripes or trim tape. It is effective for its designed use, but would prove, and has been proved, inefficient for large scale tasks.
U.S. Pat. No. 5,269,874 entitled "Portable Apparatus for Removing Heat Softenable Coverings" discloses apparatus having a rotating eraser for frictionally removing decal and adhesive material from automotive surfaces. It is activated with an electrical drill. This handheld device is designed for small applications such as pinstripe tape or trim tape removal from cars. It is effective for this limited purpose, but has been proven inefficient for large scale tasks.
U.S. Pat. No. 3,920,472 entitled "Decal Removal Method" uses a chemical system for removing adhesive. It is one part of a multi-step process and is not designed to remove vinyl decals. For this chemical to work, the decal must be previously removed.
Much larger machines that could economically clean the surface areas of typical truck trailers are known. For example, U.S. Pat. No. 5,280,662 entitled "Mobile Tunnel Surface Cleaning Machine" discloses a device using rotating brushes to clean roadway tunnels. This machine will not safely remove decals and adhesive from large motor vehicles. Adeequate heat is not supplied to soften the decal and adhesive. Further, required dynamic adjustment means for covering the large surface area presented by a fifty foot decal are missing from the invention.
U.S. Pat. No. 5,004,156 entitled "Washing Device" discloses an invention that directs hot, high pressure water against surfaces for cleaning. High pressure water will remove vinyl decals, but will not concurrently remove the underlying adhesive from the metallic surfaces being treated. A chemical solvent must be implemented to breakdown the adhesive. In addition, painted surfaces will invariably chip with a high pressure water and powerful chemical combination.
U.S. Pat. No. 4,835,811 entitled "Brushing and Washing Machine" discloses a versatile apparatus designed to wash many surfaces. However, it will not remove decals and adhesive from any metallic surface under any condition. It is specifically designed to wash surfaces to which decals are adhered and not alter or disrupt the decal in any way. The depicted machine is widely used and is very effective for its limited uses.
U.S. Pat. No. 5,133,100 discloses a "Portable Truck Washer" designed to wash tractor trailers and busses. However, tests of similar devices reveal that such structure will not remove decals and adhesive from metallic truck trailer surfaces under any conditions. This device is specifically designed to non-destructively wash over trailer surfaces and the decals that are adhered thereto. The disclosed device does not and not alter or disrupt the decal in any way. However, the disclosed machine is widely used and commercially successful. It is very effective at reliably cleaning truck trailers.
U.S. Pat. No. 2,854,680 shows a vehicle washing machine wherein the brush is suspended from an over head rail. This unit is not mobile and cannot be taken to the washing area.
U.S. Pat. No. 2,876,472 discloses a portable washing and brushing machine mounted on a fork lift truck, the machine having a rotatable brush element which is vertically mounted on a shaft driven by a hydraulic motor. A series of spray nozzles are supplied with water from a pump driven by a belt.
U.S. Pat. No. 3,680,164 discloses a mobile machine for cleaning the external surfaces of an aircraft, a brush being mounted on an articulated arm. Similarly U.S. Pat. No. 3104406 has brushes mounted on an articulated arm for cleaning road transport vehicles.
U.S. Pat. No. 3,830,430 shows a machine for cleaning the inside of a vehicle.